Ignition systems for internal combustion engines



y 9, 1963 J. M. PELIKAN 3,095,752

IGNITION SYSTEMS FOR INTERNAL COMBUSTION ENGINES Filed July 21, 1961INVENTOR JOHN M. PELIKAN BY /d m United States Patent 3,096,752 IGNITIQNSYSTEMS FOR INTERNAL CGMBUSTHON ENGINES John Mathias Pelikan, 2Yennicock Drive, Port Washington, N.Y.

Filed July 21, 1961, Ser. No. 125,689 5 (llaims. (Cl. 123-149) Thisinvention relates to ignition systems for internal combustion enginesand more particularly to ignition spark generators of the magneto typecharacterized by extreme simplicity of design.

The primary object of the invention is the provision of a sparkgenerative system for ignition purposes in which the rate of change ofthe magneto-motive forces or total flux is intense enough for effectinga spark across a preset gap only during precise intervals in relation tothe pattern of piston movement but in which the rate of change issufficiently rapid during such intervals to induce a current ofsuflicient voltage and energy to effect a spark of adequate length andintensity for ignition purposes. This eliminates the need for any timingdevices or other moving parts in the ignition system.

The above object is accomplished, in accordance with the principles ofthe present invention, by providing means preferably integrated with themoving piston itself to effect an extremely rapid build-up of amagnetizing force to a simply contructed yet eificient flux path fromwhich an induction coil may derive accurately timed sharp impulses ofhigh potential current suitable for energization of the ignition sparkgap in the engine cylinder.

The accompanying drawing illustrates physical apparatus operable in themanner suggested above and for accomplishing the objects of theinvention, and in such draWing-- FIGURE 1 is a sectional view of anignition system COIStIIlCttECl according to the principles of myinvention; an

FIGURE 2 is a modification of the system of FIG- URE 1.

Referring first to FIGURE 1, reference numeral designates the wallstructure of a cylinder of an internal combustion engine in which isslideably received a piston 11. The Wall 10 is made of cast iron orother magnetic material, and the piston 11 may be of aluminum inaccordance with usual practice. Suitably secured to the upper end ofcylinder 10 is a head structure 12 which may also be of aluminum.

Screw-threadably received in a tapped bore formed in the Wall structureis a soft iron stud 13 to the top of which is connected a horizontallydisposed bar 14 which 18 also made of soft iron to provide alow-reluctance flux path for the magnetic circuit of the apparatus.Rigidly secured to and depending from the bar 14 is a stud-like bodymember 15 also formed of low-reluctance material and which isscrew-threadably received at its lower end in an aperture formed in thehead structure 12. Body member 15 has a flat lower end 16 and apassageway or bore 17 therethrough through which extends a ceramicallyinsulated conductor 18. The bottom end of the conductor 18 cooperateswith radially inward extending points 19 attached to the inner wall ofthe bore 17 to provide a spark gap. This gap is spaced upwardly a slightdistance from the bottom 16 of the body member 15.

Encircling the body member 15 is an induction coil 20 made up of thelarge number of turns and having one end terminal of its wire connectedto the body member 15 as shown at 21 while the other terminal isconnected to the conductor 18 as shown at 22. To provide a magnetomotiveforce or source of flux a coil 23 is'wou-nd around the stud 13, andduring operation of the apparatus this coil is connected to a suitablesource of direct current.

3,096,752 Patented .luly 9, 19153 Normally, the magnetic circuitcomprised of the stud '13, bar 14 and body member 15 is open so thatlittle or no flux flows longitudinally through the body member 15 andthrough the center of the coil 20. To effect an extremely rapid build-upin this flux path to induce a high potential across the terminals of thecoil 20, a flat bar or disc 23 of magnetic material is secured on thetop of the piston 11, and as shown in the drawing, this part 23' hassliding contact with the cylinder side wall material 10. When the pistonv11 is moved to its topmost position, the block moves into very closeproximity with the flat bottom surface 16 of the body member 15. Thisaction substantially closes the air gap at the bottom surface 16 andthus substantially closes'the magnetic circuit through stud 13, bar 14.and body member 15. As this takes place, there is a very rapid build-upof total flux in the body member 15 to induce .a high potential in thecoil 20 which is applied to the spark gap through conductor 18 and thepoint or points 19. As soon as the generated potential equals or exceedsthe break-down voltage of the spark gap, an ignition spark will appearacross this gap. At low piston speeds, the rate of change of the totalflux flowing in the magnetic circuit will not reach the value requiredto generate the arcing potential until the piston is substantially inits uppermost position and the air gap almost completely eliminated. Athigher piston speeds, the required rate of change and total flux will beachieved earlier in the engine cycle whereby a degree of automatic sparkadvance will be achieved. The timing may also be controlled by adjustingthe body member 15 upwardly and outwardly, although it should beunderstood that if the air gap at the face 16 is appreciably lengtheneda higher piston speed will be required when starting the engine.

It should be particularly noted that since the flat bottom surface 16 ofthe member 15 is of appreciable area and is parallel to the top surfaceof the magnetic bridging member 23 the reluctance of the magneticcircuit will decrease very rapidly as the piston approaches the top ofits stroke thereby enabling the required rapid build-up of flux to beachieved. When the engine is on dead center the time dwell of the pistonin its upper position will, of course, stabilize the flux flow at itsmaximum intensity whereby no potential will be generated in the coil 20.However, :as the piston begins to move downward the lengthening air gapin the magnetic circuit will rapidly decrease the flow of flux andanother or second spark will appear at the gap. Normally this secondaryspark is not objectionable and may even be advantageous but. if desired,it can readily be eliminated by connecting a diode in the output circuitof the coil 20. Also, While an electromagnet (13, 23) is shown in FIGURE1 to provide the magne tomotive force, it should readily be apparentthat a permanent magnet may be substituted therefor to provide thesource of magnetic flux for the magnetic circuit. In this modification,anyone of the parts 13, 14 and 15 may in itself *be constructed as apermanent magnet.

In the embodiment of the invention shown in FIGURE 2, the arrangementand parts are generally similar to the system of FIGURE 1, the principaldifference being that the source of magnetomotive force is in the formof a permanent magnet carried on top of the piston 11. This magnet,designated by reference numeral 33, is preferably of the ceramic type toWithstand the heat of combustion in the engine and is in the form of abar, as shown. Again, the cylinder wall structure 10 is of magnetmaterial and the cylinder head, designated in FIGURE 2 by referencenumeral 12, is again preferably of some non-magnetic material such asaluminum. Magnet 33 is centrally disposed on piston 11 .and has a flatupper surface which is parallel with the flat bottom surface 16' of thebody member 15 of the spark plug structure. Again, encircling this bodymember is an induction coil 20 one terminal of which is electricallyconnected to the body member 15 as at 21' while the other outputterminal is connected to the conductor 18 which extends through anopening in the body member 15' and is insulated from this body member byporcelain insulation 34. Since the bar magnet 33 does not extend to theside wall of the cylinder, *1 provide in the upper portion of thecombustion chamber a bridging block 35 of a suitable nonretentivemagnetic material which is in contact with the magnetic material of theside Wall structure of the cylinder and which has an end face acrosswhich one end face of the magnet 33 is adapted to pass closely .as thepiston approaches the top of a stroke. Again, the air gap in themagnetic circuit is rapidly and efliciently closed by the relativeclosing movement of the large flat surfaces 16 and the top of bar 33.

The principle of operation of the assembly of FIGURE 2 is substantiallythe same as in the embodiment of FIG- URE 1, it being apparent that asthe piston 11 and magnet 33 approach the upper end of their stroke themagnetic circuit comprised of the stud 13, bar 14, body member 15',magnet 33, block 35, and a portion of the cylinder wall, will besubstantially closed. Simultaneously the magnetomotive force supplied bythe magnet 33 will be coupled into this circuit so that a rapid build-upof flux in the same will be effected as the piston approaches the upperend of its stroke. This change of flux density in the coil induces ahigh voltage therein to energize the spark gap shown as comprised of thelower end of conductor 18 and the point or points which extend inwardlyfrom the annular lower portion of the body member 15.

In either of the disclosed embodiments of the invention the coils andconductors which may be otherwise subject to water and moisture damagemay be completely encapsulated in a suitable water and moisture-proofmaterial so that theoretically the engine can operate under water if asuitable air intake and exhaust is provided.

It should now be apparent that I have provided an improved ignitionsystem for internal combustion engines of the magneto type which doesnot require any moving parts in addition to the conventional piston ofthe engine, which is very simple in design and thus inexpensive toconstruct, and which inherently controls the timing of the spark inrelation to the cycle of movement of the piston. Further, the systemprovides for an automatic spark advance in relation to the speed ofpiston travel and therefore in relation to the r.p.m. output of thecrankshaft of the engine. Also, since the ignition system of theinvention does not require any moving parts on the outside of thecombustion chamber, the system may be completely encapsulated and thusremain operative under severe water and moisture conditions. In bothembodiments of the invention illustrated, the spark plug assembly may bereadily adjusted inwardly and outwardly of the cylinder to vary thedimension of the final air gap or to regulate the timing as describedabove. The threaded shanks of the body members 15 and 15 of the sparkplug structures are sufficiently long to accommodate the lock nutsshown, and it should be apparent that upon loosing these devices thebody members 15 and 15 may be finely adjusted inwardly or outwardly, asdesired.

Having thus described my invention what I claim is new and desire tosecure by Letters Patent is:

1. An ignition system; for an internal combustion engine of the kindhaving a piston and a cylinder whose side Wall structure is of magneticmaterial while its head is of non-magnetic material; means extendingthrough said head to a position closely adjacent the top portion of saidpiston in said cylinder and connected to said structure to establish alow reluctance flux path, an induction coil encircling said path, meansincluding the first mentioned means .and an insulated conductor leadinginto the combustion space of said cylinder for establishing a high tension circuit terminating at a spark gap within said space, said circuitbeing connected to the output of said coil,

means establishing a magnetomotive force, and means operative upon saidpiston reaching its top position to substantially close said path andtoapply said force to said path whereby the rapid buildup of flux in thepath within said coil will generate a high-voltage surge in said circuitto energize the spark gap as the piston approaches the top of itsstroke.

2. An ignition system; for an internal combustion engine of the kindhaving a piston and a cylinder whose side wall structure is of magneticmaterial while its head is of non-magnetic material; a plug having abody member of magnetic current-conductive material extending throughsaid head to an adjusted position wherein its inner end is closelyspaced from the top position of said piston, means interconnecting saidstructure and member to establish a low-reluctance flux path, aninduction coil about said path, an insulated conductor extending throughsaid member and forming at its inner end a spark gap with said member,said coil having its output connected to said member and conductor,means establishing a magnetomotive force, and means carried by the upperend of said piston to substantially close said path and to apply saidforce to said path whereby the rapid build-up of flux in the path withinsaid coil will generate a high-voltage surge to energize the spark gapas the piston approaches the top of its stroke.

3. An ignition system for an engine having a com bustion chamber and apiston slideable therein compris ing a normally open low-reluctancemagnetic circuit, an induction coil encircling said circuit andconnected to a spark gap within said chamber, means to provide amagnetomotive force, and means operative upon said piston reaching itstop position to rapidly and substantially close said magnetic circuitwhile effectively applying said force to said cirrcuit whereby the rapidbuild-up of flux in said circuit will induce a high voltage surge insaid coil to energize the spark gap as the piston approaches the top ofits stroke, said magnetic circuit including a flat fixed pole face andsaid operative means comprising a bridging piece of magnetic materialcarried by the upper end of the piston and having a flat pole faceparallel with said fixed pole face, said faces being so' oriented as tohave relative movement normal to their planes.

4. An ignition system for an engine having a combustion chamber and apiston slideable therein comprising a normally open low-reluctancemagnetic circuit, an induction coil encircling said circuit andconnected to a spark gap within said chamber, means to provide amagnetomotive force, and means operative upon said piston reaching itstop position to rapidly and substantially close said magnetic circuitwhile effectively applyingsaid force to said circuit whereby the rapidbuild-up of flux in said circuit will induce a high voltage surge insaid coil to energize the spark gap as the piston approaches the top ofits stroke, said chamber being formed of magnetic material at least inits side wall and said magnetic circuit being connected to said materialand including a magnetic current-conductive plug extending through thehead wall of said chamber, said plug having a longitudinal bore thereinfor the passage of a ceramically insulated conductor forming at itslower end one terminal of said gap, said plug having a flat bottomsurface, and at least an appreciable thickness of the top extremity ofsaid piston being formed of magnetic material having a flat top surfaceadapted to move into close proximity with the bottom surface of saidplug to thereby substantially close said magnetic circuit.

5. A system according to claim 4 in which said plug is adjustable as tovertical position with respect to the cylinder to vary the thickness ofthe air gap between said flat surfaces.

References Cited in the file of this patent UNITED STATES PATENTS585,755 Haselwander July 6, 1897

1. AN IGNITION SYSTEM; FOR AN INTERNAL COMBUSTION ENGINE OF THE KINDHAVING A PISTON AND A CYLINDER WHOSE SIDE WALL STRUCTURE IS OF MAGNETICMATERIAL WHILW ITS HEAD IS OF NON-MAGNETIC MATERIAL; MEANS EXTENDINGTHROUGH SAID HEAD TO A POSITION CLOSELY ADJACENT TJE TOP PORTION OF SAIDPISTON IN SAID CYLINDER AND CONNECTED TO SAID STRUCTURE TO ESTABLISH ALOW RELUCTANCE FLUX PATH, AN INDUCTION CAIL ENCIRCLING SAID PATH, MEANSINCLUDING THE FIRST MENTIONED MEANS AND AN INSULATED CONDUCTOR LEADINGIN TO THE COMBUSTION SPACE OF SAID CYLINDER FOR ESTABLINHING A HIGHTENSION CIRCUIT TERMINATING AT A SPARK GAP WITHIN SAID SPACE,